Like the ‘50s jet age and space age of the ‘60s, “rotary power” was a hot topic across the 1970s automotive sphere. Billed by apostles as the next phase in internal combustion, it was, for a time, just that. The principle was deceptively simple. It features a three-sided rotor (almost triangular in shape) spinning around a crankshaft inside an oval-esque combustion chamber, which provides three power cycles for every revolution of the rotor. Confused yet? Many smart people were despite the fact that a basic rotary engine has just two moving parts. Check out this link for a good animation.